Fastening device



FIG. 1 is a front, left and top perspective view of a fastening device embodying my new design;

FIG. 2 is a rear, right and top perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a top view thereof.

The broken lines in the drawings illustrate portions of the fastening device and form no part of the claimed design. 

CLAIM The ornamental design for a fastening device, as shown and described. 